There is a well-defined, round lesion within the upper pole of the right kidney. The lesion has homogeneous high signal intensity on T1WI, and heterogeneous low signal on T2WI. Signal loss between the in-phase and out-of-phase images indicates the presence of fat. On the contrast-enhanced scan, the lesion has marked enhancement on the venous image, with slight wash out on the delayed image. The diagnosis of an angiomyolipoma was confirmed by pathologic examination.